Abstract: A disc array connecting system in which a malfunctioning device can be identified easily to render it possible to shorten the time involved in identification processing. A switch circuit 12 in an FC-AL concentrator 1 interconnects an initiator host 2 and plural target disc arrays 3-1 to 3-3. A malfunction detection circuit 11 detects a malfunction occurring in a network to which are interconnected the initiator host 2 and the plural target disc arrays 3-1 to 3-3. A switch control circuit 10 control the switch circuit 12 and, as it disconnects only a malfunctioning device from the system, sequentially and individuality interconnects the target disc arrays 3-1 to 3-3 to the initiator host 2. It is possible to identify or detect a malfunctioning device from the state of connection in the switch circuit 12.